Best preamp is no preamp: always true?

I have had many active and passive preamps under different system configurations. In some cases a preamp wasmandatory and made huge effect in the sonics and presentation, in some others a passive preamp or no preamp (asI have now my system) wotks the best.

Sorry - no golden-rule here from my experience.

I'd like to prepsent a few facts which may help you to understand this complex issue. Because the answer is "it depends".

1st, if we look back 40 yesrs ago, we did not have high output sources. So it was a must to have preamp not only to switch sources but to amplify the signal for the amps. So, the amps were not buit as sesitive as todays amps. Not only that most speakers were very efficient. When CDP first came out they also had much lower output(less than 1v) than todays CDP(2v).

2nd, the only things in audio chaine which does not amplify the signal is the phono pickup and DAC chip. As soon as the signal leaves the TRUE source each component amplifies the signal including the source equipment.

3rd, amplification process doesn't make the input signal bigger. It make a bigger COPY of the input and discard the original. So, as soon as the original leaves the TRUE source, its forever gone and only the COPY handed down.

4th, all amplification process react to the demand from Down Stream and pass that to the Up Stream. Which means, speaker demand reachs all the way up to the very first amplification. Which also means, if the Mid Stream amplification can meet the demand of DS less demand goes to US.

5th, eash pomponent has multiple amp/gain stages. Two to as many as five. Less can be better but demands much better performance from US.

6th, many of todays speakers are very inefficient. Impedence drops too low which put much high demand up the chain.

I'm a purist and I don't use pre nither active nor passive. I'm using Meridian digital pre infront of the DAC. My DAC is Denon DVD5000 which I had disable the entire DVD section route all poower to DAC section and re bias its output to class A resulting 4v of output from the 2v. And all my amps are very sensitive which requires only .5 to 1v of input. I'm a SET guy and most of them are naturally sesitive.

More often than not it will be your speakers calling the shot.

Best regards...

Sugarbrie, you have a Creek integrated and an Onkyo receiver. So where's the preamp????

I tried a Placette RVC, with .5 meter Audioquest Jaguar cables to my Mcintosh MC 2000 amp.
It lacked dynamics. The music lacked life. My Supratek Grange, is 1,000 times better.

I have also done the expermient with hooking my cd player directly up to the amp. A pre amp to me just seems to pull together a more musical presentation.

A passive preamp will often sound better than an active but that is only because most active pre's are poor.When you discover a really good active pre-like the Suprateks,it becomes obvious that the preamp is actually more important than the power amp.You can never achieve good sound from a system using a good power amp and an average pre but you can get great sound from a good pre and an average power amp.

JT

active preamp. The only direct CD connection I have heard and liked was a $6K Wadia. For that you can buy a great CD and pre while maintaining flexibility.

For what it's worth, I've found my Levinson 390S running directly into my CAT JL-3's to sound much better without my ARC Ref 2 Mk II. Of course, the 390S DOES have the same analog volume control found in Levinson preamps.

Solman989,
In case of integrated amps you ought to figure that the amplification part does it all where the volume pot usually connected onto the driving stage(realy becomes active after all)

In some of the passive-stage integrated amps you may feel the lack of drive and controll f.ex. Creek 4330. At the same time I could contradict myself saying that it just hasn't enough watts, but after trying it to work as poweramp only with active drive it was way different:
Still lack of power but controll increased no doubt.

Another of my discoveries would state that you can add even a chain of preamps and you will gain even more and more controll but to the point where's your music would become overcompressed since every preamp would invert signal i.e. make a negative feedback level deeper.

Counterpoint power amplifiers have option to have a high impedance/sensitivity driving stage specially designed for the passive preamps. This driving stage isn't recommended for the best product performance to whoever prefers active preamplification... Which means that preamplification and driving stages should be just enough not to get high level of a signal compression and so I guess that hobbyist who's matching components should pay to some degree an attention to this factor such as a number of preamplification and driving stages of mainly separate amplification components.

Yes I have. I've tried this with my passive integrated. It sounds much better when you have the active gain stage involved.Without it the sound is clear and precise but a tad thin without the help from a tube linestage. After trying it both ways I couldn't see going without the active linestage/ gain-stage in the loop. I liked the sound so much I'm getting a unit built without the volume control that is nothing more than a low gain active stage to go between my DAC and Integrated.

Add to the list of integrated amps with a passive input the Ayre AX-7e.

I have not heard any of these (passive input) integrateds. I would like to, though. Their power amp sections were designed specifically to be run with a passive pre' section (I presume) and so would most likely do just fine---more than fine---in this configuration, especially with a high output, low impedance CDP or DAC.

Could these integrateds be tested with and w/o an active pre-amp by turning the volume all the way up on the Int amp and use it with an active pre'? And then take the pre' out and use the volume control on the int amp as usual? Has anybody tried this with such an integrated amp?

Does the Berning 270 amp have a passive input section?

Dave, that's what I thought. As usuall it carried a good thought as well.

Unsound

Thought I better stir pot.

Dave

Sogood51, sarcasm aside, these passively integrated units do have some advantages. They have less connectors and may have much less cable to drive. Due to size, weight and heat issues, in practice most of these passive integrated units will be limited in power output. High powered passive integrateds will probably be too cumbersome for most to use conviently. The irony is if one were to use remote control and place these passive integrateds where traditional power amps usually go, one would probably need many longer interconnects from source components to facitlitate their use. Of course multi-amping becomes more problematic as well.

Solman989

You can add the Manley Stingray to your list also. I guess no one will be wanting to own these integrated components now that you have let this cat out of the bag...they must sound very dull and lifeless.

Dave

I can only tell you what my ears told me. At the present time I am running a modest system with early Maggie I series, Threshold S/150, Sony Dvp 7000 with mods on all the above. My preamp consisted of an entry level Audio Note M Zero, although a budget preamp I found it to have very pleaseing sonics. But you know I wanted more and being that the Sony DVP 7000 was know as a better transport than player I thought I should try an outboard Dac. Enter the Benchmark Dac which I played for 3 weekend days ( lots of hours )and I ran it through my preamp then as the manual says I thought I would try it without the preamp. WOW !! the difference was stunning, much better sound stage, more dynamic, much more bloom in the instrument. Why would I run it through my preamp after this. I sold the Audio Note and go from my CDP-Dac-Amp, the benchmark Dac I believe does have an active gain stage for volume. Had I had a better preamp I might not have noticed the big difference. But I really like what I hear now. I'm on a budget but I will say I live in Vancouver and have been thinking about trying a preamp from a local builder known as Space Tech. Labs which has had some good reviews.

What about integrateds with a passive preamp built in? The Portal Panache or Song Audio's Vasant_K are basically configured as a power amp with a passive volume attenuator and input selector. I have not listened to these integrateds but have heard positive comments from satified users. Do these units exhibit the typical characteristics of a passive preamp (lacking dynamics, requires high input voltage from source, etc)?

Marakanetz, you make a good point. I guess it would be possible to have a high out put CD player with decent volume control of some kind and maybe a power amp with a good input section to combine to take the place of a pre-amp.

Someone else on this thread pointed out (I think), though, that the likelihood that the volume controls on most variable out CDP's will compete with the attenuators on good pre-amps is somewhat low---all other things being equal.

There is also the issue of impedance matching. Are there enough variable out CDP's that also have both sufficient gain and low impedance to "drive" an appropriately equipped (sufficient input stage) power amp properly? I don't know. Maybe this has been covered elsewhere in this thread. Sorry for the redundancy, if so.

Grannyring, Thanks for the corroboration. We just haven't heard a pre'-less setup done right, I suppose.

You may not need it functionally, but my ears say you need it for the best sound performance.

A meaning of a PREAMP(POWER-AMP) is relatively new v.s. previouse meaning of just an AMPLIFIER.
Whatever we take as PREAMP is actually the part of an AMPLIFIER.
So depending on a number of an input(driving) stages of the amplifier you may or maynot need active preamplification.

Kalan you are right. I posted above and tried the passive and no preamp thing. A good active preamp always sounded better. It may be possible that in a certain set-up no pre or a passive pre is better, but I HAVE NEVER HEARD IT COME OUT THAT WAY.
I tried with many different combo's of gear and the active pre always won out pretty easily. I personally think those who find a passive or no pre to sound better like a "certain" type of sound. That type of sound is a little on the lean side. To some this sounds more detailed and transparent. I think one perceives this and is tricked by the overall leaness of the presentation. Bottom line, the preless or passive camp just likes it more and that is cool!
Wish I did as I could save money without a pre.

Bill

Dovetail asked Bigkidz (in this thread, I think) what the discussion with First Sound entailed about volume pots or attenuators, etc.

While I have no way of knowing what Bigkidz and Emmanuel Go (First Sound) might have spoken about, the First Sound website says their stepped attenuators are made with Holco or Vishay resistors. I believe the upper models have the Vishays.

I have tried a passive pre-amp (First Sound, before they went to the active design) and have heard many systems with and without pre-amps. My system sounds better with the First Sound Active pre-amp than with the passive (or without a pre-amp at all). Several folks I know have tried the same experiment; they all prefer their systems with a good active pre-amp. Doesn't mean that no pre' can't be done well; I just haven't heard it.

I've tried two passive solutions in my system - a Bent Audio TVC with copper transformers and a built-in resistor attenuator in my Audion Silver Night. I've tried various configurations: I've used the Bent with five different amps, both tube and solid-state, and I've tried the Audion nude, with the Bent and with a couple of actives. This has been done on two different speaker systems, both of them efficient and high-res. The source is a balanced AN DAC, with quite low output impedance and sufficient, though not excessive output voltage.

The conclusions that have remained relatively consistent across most configurations are:

- The Bent was sonically problematic in all my configurations. It's very smooth, but robs enough dynamics and detail to make the sound boring.

- The tube preamps I've tried (Canary and Audion) have better dynamics than the Bent, but equivalent detail and higher noise. They tended to be more fun to listen to, but were more coloured (warmer).

- The resistor attenuator in the Audion sounds quite good nude. Putting the Bent or one of the tube preamps in front of it mucked up the sound in various ways.

- The joker in the deck is the solid state Tom Evans Vibe/Pulse. I tried it with three amps, and it produced better sound than any of the others. It even improved the sound of the Audion amp when driving its internal attenuator. Imprevements were in the areas of bass and treble extension, dynamics, detail, neutrality and transparency. The downside of course is that it is two to four times the price of any of the others. I ascribe the superiority of the Vibe to its higher output current and lower output impedance.

So, a passive can be better than a medium-high quality line stage (the case with the Audion's attenuator), or it may be worse (like the Bent). A very good preamp is likely to exceed the quality of a passive because of its current and impedance advantages.

Well, lets see...I can think of a member here at Audiogon with a mega buck system that uses (or at least did use) a passive in his system....I don't think he's hard of hearing, and he's sure not a newbee.

If I recall he had the Placette Audio passive in his system.

Dave

Check out the discussion and review of a passive inductive preamp in the January 2006 issue of Stereophile.

I have never heard a situation, where price was not a limitation, where NO preamp or where a passive preamp was superior to a really good, system-matched linestage. I know the mantra about sufficient output and compatible input and output impedance and short cable run, etc., but even in systems that don't need any gain from source (like mine), a good active linestage simply sounds more dynamic, projects a more realistic image, and pulls the listener into the performance in a way I've not heard passive linestages do. I suspect that the putative superiority of passive units may be a superiority AT A PARTICULAR PRICE POINT, but not absolute superiority.

Now, as far as NO preamp at all, with digital sources, one would have to consider whether the volume control is digital or conventional (variable resistance). I don't know if it really is the case, but a lot of listeners claim that the truncating of low level bits to achieve digital volume reduction is not sonically desirable, so playing the source at maximum volume and attenuating with an outside volume control is superior. If the digital source has an analogue volume control, I suppose the issue is whether that volume pot is better built than that in the linestage it is hooked up to -- if it is inferior, one again might get better results by setting it at maximum and using the linestage volume control to attenuate the signal.

We have the same fancy (or as they say in the car industry, "pants") CD player as TVAD, and also find that we prefer having the preamp in the chain. It allows for better separation of the instruments, a preferable 'gain floor' as a complimentary support to the amps, and it conveys a more meaningful heft and density to the music. If we run direct--and our player does have an outstanding hybrid attenuator--the soundstage collapses, and on anything other than light chamber music, vocals or soft jazz, I'm just not feeling it. We take the preamp out, and it sounds like the music is struggling to get out, losing a sense of ease and realism in the process.

Some people will choose a configuration according to sonic preferences, while others wouldn't think of adding the preamp in the interest of maintaining a purist's approach. As TVAD suggests, you'll have to decide for yourself.

If CD playback is your only source then you'll just need to get an expensive CD player with high output + volume control. In this case, the "less" component is better off.
This is different from having a passive preamp. I would go with that than having a passive preamp in between the sounce and amp.
The ONLY drawback is CD player choice. You will be limited to less than a dozen of expensive players to choose from.

As far as DAC goes, it is same idea as CD player with volume control. In this case, you'll be limited with DAC that has high output plus build-in volume control.

I've tried it in the past and it's not bad. But the preamp/buffer stage makes it a whole lot better IMHO. It never sounded slow or fat. Just slightly hard on cymbals and such. It's like having too much of a good thing that wears on you over time.

Newerphile, My opinion, lost dynamics and frequency extremes, could sound flat and yes make it seem more like a digital boring source. maybe not every case but in most, basically look at it this way a preamp is sorta line level amplification like an EQ would be, it will boost some of the frequencys to a fuller sounding range not because that is really its intention but because no matter what you are playing with the tiny voltage signal coming from the cd and any extra gain added to a signal that small well will sound like 10 times more effective than going from like a 50 watt amplifier to a 350 watt amplifier if that makes sense, is it pure?, is it Zero distortion?, nothing is, but the closest it sounds like emotion in the music the better in the end, this is mostly achieved by using a preamp in the chain than not from my experiance.

Actually, I have been reading and hearing more and more that CDP into AMP direct is very very seldom a good idea. I think you guys have highlighted gain and impedance issues as possible cause. What would be a typical sound "default" of a direct CDP to AMP? too harsh a sound (digital glare) or, opposite, slow/fatty mid-range ? or it varies?
Thanks

I lived with a Sonic Euphoria passive pre between my Pass amp and my Dodson DAC. It was incredibly transparent and revealing. It showed me just how good the Dodson and Pass are. That said, I preferred the sound of my system with the Modwright preamp in the chain.

I have never heard a CDP direct to amp that I could live with.

HI,
First post. It defies logic but I just installed a Krell KAV 280P pre between my power amp and tube DAC. And yes it does sound better. Better detail, better dynamics. Don't know why. Don't care.

Sparky

Intuitively the answer is Yes. However, in practice in ain't necessarily so I've found. My Wadia 6i will drive the ARC VT100 direct but I can truly detect no difference if I insert the ARC Ref 2. As a purist I wanted it to be better but I can't honestly say it was.
Maybe it boils down to the quality of the CD output stage?
Anyway, no rules or opinions can replace YOUR ear. If you like it that way - listen to it that way.

3V is almost double the volume of 2V. It sounds more normal while 2V sounded sleepy and slow and weak.
There are few CD players gives you 3V output but it all comes with $$$ price tag.
Meridian
Accuphase
Wadia

Not sure about others since I didn't measure them.

Can you explain to me why you fell that 2V is not enough for passive if the amp has, for example, 0.4V input sensitivity? I trust your experience and will likely go active but that puzzles me a little.
Thanks

"From my experience, 3V is min for passive"

I pretty much agree with you, my experience as well.

Dave

From my experience, 3V is min for passive. I have 2V CD players and it just not enough gain

newerphile,

"I guess I am free to listen to any preamp then..."

Careful. A resistive passive can interact with interconnect cable capacitance to form a low-pass filter so one should evaluate the other components in the system.

Read this:
http://www.dact.com/html/passive_preamp.html
from the DACT commercial web site and also maybe use this:
http://www.dact.com/html/ac_calculator.html
their attenuation calculator.

There are other, less commercial, technical papers on passive preamps which will probably be revealed with a google search. I can't put my finger on them right now. Also, maybe try the DIY forum over at audio asylum.

newerphile,
Yes. There are some obvious measureable things to avoid otherwise you may possibly be covering up one ill with another. However, I think the general concensus is that, once you have the right gain level and impedences matched, always trust your ears.

S23chang: I think it will come down to that!
I looked upon the specs of my source and my amp and I see no particular problem with gain (out 2v, in 0.4v), nor impedance (out 325, in 35k). I guess I am free to listen to any preamp then, active or passive!!!!

Pick your preference and use your ear.
Afterall, your ear will enjoy the most : )

Thanks. So now the ultimate question: it seems that there is a strong measurable factors rationale behind the use of the appropriate active PRE, namely impedance, gain, etc. Does this mean that it is safe to shop based on measurements that "match" the rest of my system to short-list a few PREs or is it a case of meaningless measurements and the "perfect" match is purely based on listening?
Thanks, this is a great source of info for a newbie like me.

smokester - very interesting response. I have been researching passive preamps of late and have been getting quite confused in the process. Resistive versus transformer-based versus autoformers, where does it end. Interestingly I had a conversation with the owner of First Sound yesterday as I was interested in their passive preamp. Bottom line, he suggested I look into one of his active preamps. Go figure... (no pun intended).

newerphile,
It's just not a universally correct conclusion that passives are better.

I think one of the flaws in the "passives are universally better" school is that cables are regarded as having unity gain independent of frequency. In fact, cables (and their interactions with components) contribute to a network which can have an audible frequency dependence. One of the most important jobs of a preamp is to match the output impedance of the source plus its cable's capacitance to the input cable and input impedance of the power amplifer.

A confounding factor for resistive passives is that the effect they can have on frequency response depends on their setting. In some circumstances, higher volume settings will attenuate the highs more. If the power amp gets harsh at loud volumes this can be a "good" thing.

At an earlier stage in my system evolution I had a Tom Evans Microgroove phono amp driving a tube power amp through a resistive bridge passive attenuator and it worked fine--probably because the Microgroove had very low output impedance (hard to get the specs). However, my present tubed phonoamp absolutely requires a preamp (CJ Premiere 16 2)for uniform frequency response.

Then there is the question of overall system gain required to achieve the sound levels required. Most modern digital players are capable of producing output voltages that will saturate the power amplifer. Thus, their outputs need to be attenuated and extraneous amplification is just adding noise...or perhaps masking an undesireable artifact from the source. Still, an active preamp may be required to achieve the proper impedance matching.

In the case of vinyl-based sources with low output cartridges there may be a requirement for additional gain to be made up by the preamp as is the case in my present configuration.

It can take a pretty good (read expensive) active preamp, and a highly resolving system, to start hearing the impacts referred to above. If a system is put together appropriately a passive will do just fine.

The choice for passive versus active preamps is highly system dependent and there is no universal "always true" answer.

Thanks a lot guys, I am surprised to see that there seems to be a consensus around active PREs that easily...so, when people talk about passive PREs and how it maintain the integrity of the original signal "no more, no less", could it be that it is in fact "less" (degradation of signal)and also a little bit of audio snobbery to KISS when in reality the signal needs to be restored by some active mechanisms?

S23chang I think in theory and practice to our ears that could be very true. Also the fact that the meitner comment provides good proof to practice, as I would agree that should be as good as a seperate pre if not better in some case's

I think there is only one theory: The moment signal left the source it is already degrading.
The active preamp helps restore some of the lost signals while the passive just let it flow through.

My experience mimics that of Matrix, and that includes having run both the Audio Aero Capitole and the APL 3910 direct, two very fine CD players in my book.

It's interesting that Ed Meitner provides a full-function active preamp in his EMM DCC2 dac instead of a simple gain control.